In order to impart additional lift to powered aircraft either for pleasure or business use, it is conventional to extend the air foil at the leading edge of the aircraft wing by means of a sheet like member or leading edge flap which folds outwardly from the bottom surface of the airfoil type wing, at its leading edge, and pivots to a position generally in line with the convex curvature provided to the wing at its upper surface such that the sheet like member functions as an extension to the leading edge of the wing itself, and acts as an extension of the upper lifting surface of the wing.
In larger, and thus heavier, aircraft, since the leading edge flap, known as a Kreuger flap, extends over a major distance of the leading edge of the wing, multiple motors have been employed for acting in concert to drive the Kreuger flap from its retracted position lying flush with and/or forming a portion of the lower surface of the wing, adjacent the leading edge thereof, to a projected position approximately 90.degree. thereto, where the Kreuger flap forms a virtual extension of the convex upper surface of the wing.
As may be appreciated, it is desirable to maintain the aircraft structure as lightweight as possible to improve the fuel economy of the aircraft. Fuel economy is a very important factor, particularly due to the tremendous increase in cost of aircraft fuel as result of the world oil shortage over recent years. Additionally, Kreuger flap actuating mechanisms in the past are costly due to the utilization of multiple drive motors such as hydraulic cylinders for effecting flap movement between projected and retracted positions at the leading edge of the wing.
It is, therefore, a primary object of the present invention to provide an improved Kreuger flap actuating mechanism for a light aircraft which is positive in operation, which mechanism mechanically locks itself in both retracted and projected position, is spring biased towards retracted position and wherein a single drive motor may be employed for effecting movement of the Kreuger flap from extended to projected positions, and vice versa.